I often joke that being a reliability engineer makes it difficult to get on an airplane. Yet air travel is by far the safest method of transportation. Maybe I just think about failure too much.

When a project manager views the day’s tasks, she sees timelines, connections, dependencies. When a marketing manager views a product idea, she sees benefits, sales channels, and profits. When a reliability engineer views a prototype, she sees the many ways it can fail

Underlying how we view the world includes our assumptions, reasoning, and experience. We understand the world around us via the set of filters we use. We form conclusions and make decisions much the same way. Quickly and mostly automatically.

When faced with an important decision, building a plan, or making an important proposal we should deliberately shift from auto-mode to critical-thinking-mode. Question assumptions, reason through logic and diversify thought, done consciously helps us to create our best work.

Question Assumptions

As engineers, we make assumptions in order to solve problems. The homogeneous blending of materials, statistical independence, minimal measurement error, etc. Some assumptions set that framework for the scope of work or realm of application.

As a minimum be clear about the assumptions involved in framing a problem, bounding a process, or limiting a solution. Write them down.

Which assumptions if not true or close to true would materially change your thinking, outcome, or decision? It is this line of questioning that allows you to better understand the stage of your work.

Simply assuming a constant hazard rate greatly simplifies a wide range of reliability statistics and test planning. It also obscures the very information we seek to expose and understand, such that occurs with decreasing or increasing hazard rates.

When faced with an important task, step back for just a moment and expose the assumptions involved. Are they true, how do you know, what is the evidence? It may just change how you view the issue or reveal a better solution. Or not.

Reason Through Logic

When learning to write essays in school, our teacher regularly started the lesson with a bit of fallacious reasoning. Sometimes we caught the logic error, often didn’t know why it the argument was faulty, and sometimes we’re deceived by the error.

As an example: Product X and Y were both designed in three months. Both products perform reliably. Therefore, any product designed in three months will be reliable.

What is the issue here? Can you name the logic fault?

In school, we learned to identify 15 different faulty arguments and to name them. My favorite being a red herring (an element designed to distract the reader from the main point of the argument). Poisoning the Well, Non-Sequitur, Unsupported Generalization (the issue with the example above, btw) are just a few of the many ways we craft faulty arguments.

Write down the logical elements that frame an issue or process. Write down the arguments involved. Does logic work? Are there any errors in reasoning lurking about allowing you to make a critical mistake?

Diversify Thought

We all have our own unique set of experiences. It creates a framework with which we view the world. Furthermore, there are groups that share many experiences and to some extent view the world the same way.

The ongoing effort to include more women in corporate boards is in part an attempt to inject a different world view on the board typically make up of only white males.

Different people, and groups of people with similar experiences, view the world in different ways. When I view a product I see how it may fail. When a marketing manager views a product she sees the benefits the product creates for customers.

As we expose assumptions and review the logic, we are using our set of filters and are likely to miss critical aspects that we shouldn’t. By asking those with similar world views, we are likely to get similar sets of filters examining the issue and similar results. While that may seem refreshing that our approach is supported by someone else it is a problem.

What we need when facing a critical tasks is the ability to view what we see with a different perspective. Someone that runs the details through and exposes different options and traps.

Asking fellow engineers to review a proposal may not reveal the same insights as asking for feedback from senior managers or shop floor operators. When considering product use profiles, is the way you use it the only way? Most likely not. In practice, get input and feedback from a range of people that have significantly different sets of experiences than yourselves.

Make Critical-Thinking-Mode a Habit

Thinking is governed by our behavioral habits. Changing a behavior is tough. It take time. Like six weeks of daily deliberate practice as a minimum. Yet, considering assumptions, logic, and diversity will help your ability to think clearly.

To get started, create a short checklist:

• Question assumptions
• Reason through logic
• Diversify thought

Post is somewhere visible, where you spend your time thinking through the tasks and challenges. Practice, get feedback, practice some more. Everyday. Practice with simple tasks as well. Make this three-step process natural for you.

You may believe you do these three steps already and to some extent you probably do. Now make is deliberate. Make this practice something you bring out as a conscious effort. The insights around your critical reliability thinking will help you improve.

This article inspired by the Harvard Business Review article “3 Simple Habits to Improve Your Critical Thinking” by Helen Lee Bouygues, dated May 06, 2019.

For a listing and short examples of 15 logic errors, see the Pennington Publishing Blog entry “The Top 15 Errors in Reasoning” by Mark Pennington, dated January 14, 2009.